Speakers of the Numbami language in Papua New Guinea employ bifurcate merging, Iroquois-typekinship terminology. One of the major classificatory criteria of such a system is whether a chain of relationships crosses sex lines or stays within the same sex. For instance, siblings of the same sex (parallel siblings) are distinguished according to whether they are elder or younger than oneself (ego). Siblings of the opposite sex (cross-siblings) are not. Similarly, one’s father’s brothers and mother’s sisters are distinguished according to whether they are elder or younger than the respective parent, and their children (parallel cousins) are classified as either elder or younger parallel siblings in accordance with the relative age of their parents.

In contrast, relative age is not regularly distinguished for relatives linked across sex lines, such as one’s father’s sister’s children or mother’s brother’s children (cross-cousins). This lack of age-ranking among cross-cousins (and perhaps marriageability) may suggest why the gode-lu-gode (‘cousin-to-cousin’) relationship is considered the most open and easygoing kin relationship among the Numbami.

Nearly every major kin category is indicated by a pair of forms that distinguish female from male members of the same category. The term for females is usually derived from the base form by means of a suffix, usually -ewe, that is transparently related to ewa ‘woman, female’. (The nasal that often intervenes is discussed below.) Whenever there is a derived female-specific counterpart, the base form usually refers only to males, but it can also be used to refer to all members of the particular kinship status, whether male or female.

tamota ‘nephew (son of cross-sibling or cross-cousin)’tamotewe ‘niece (daughter of cross-sibling or cross-cousin)’

The female suffix is most likely responsible for preserving the last vestiges of an intervening set of possessive suffixes that have been lost everywhere except on a handful of these kin terms. Even where the suffixes survive, however, they do not constitute a full paradigm (only singulars) and are highly variable in usage. Moreover, they are always redundant. Except when they appear on vocatives, they are always accompanied by the preposed possessive pronouns. Whenever there is doubt about which form to use, the ending -n-ewe, which used to signal a 3rd person singular possessor, appears to be the safest choice.

It may not be coincidental that the word bumewe ‘European[s], white[s]’ looks like a term for females. Compare Iwalpupkawe ‘European’, avie ‘woman’, but Jabêmbômbôm ‘European’, bômbômò ‘European female’.

Bifurcate-merging terminology also shows up in older varieties of Tok Pisin (and other Pacific pidgins/creoles/Englishes), where for some speakers brata (< ‘brother’) can mean ‘parallel sibling’, while susa (< Eng. ‘European’) can mean ‘cross-sibling’ (as defined above). So a female might be referring to her brother when she says susa bilong mi and might be referring to her sister when she says brata bilong mi.